The use of multi-stranded aluminum wire has been retarded because of the problems of reliably attaching the wire to a terminal at a reasonable cost. Further, the use of aluminum wire has been impeded by failures of prior art terminals wherein the failure has been catastrophic; i.e., sudden, rather than a gradual deterioration such as experienced with conventional copper conductors and brass, copper or other like terminals.
One well known problem with aluminum wire is its ability; i.e., the several individual strands to move or creep under temperature cycling common to all electrical connections. This phenomenon had for years prevented the use of conventional crimping technique on aluminum wire.
Terminals which are attached to electrical conductors through crimping techniques are either open or closed barrel.
The open barrel terminal is one having a U-shape; i.e., a floor bounded on two sides by vertical sidewalls. In crimping, the wire is laid on the floor and the walls are folded or otherwise wrapped around the wire into an encompassing relation.
A closed barrel terminal is one having a hollow cylinder in which the conductor is received. The cylinder or portion thereof is collapsed down onto the wire squeezing such thereinbetween.
With respect to terminating multi-stranded aluminum wire, workers in the field have been successful in crimping such in closed barrel terminals wherein perforated liners are employed. These liners, placed in the hollow cylinder and around the wire, serve to break up aluminum oxides and further to cause the strands to be squeezed into the perforations. These actions result in good electrical and mechanical terminations. One such example of a closed barrel aluminum termination is disclosed in U.S. application Ser. No. 346,530, filed on Mar. 29, 1973, now abandoned, the disclosure being incorporated herein by reference.
Contra, aluminum termination in open barrel terminals have not met with a high degree of acceptability. One reason therefore relates to the aforementioned creep phenomenon. Another problem, common to both type of terminals but more conducive in open barrel terminals, is corrosion, particularly galvanic corrosion.
Accordingly it is an object of the present invention to provide a terminal and a method of terminating an electrical wire therein which will cause inter-strand bonding so that the individual strands cannot move but as a unit and that movement thereof is prevented by extruding wire into cavities located on the sidewalls of the terminal.